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101.
Selective transfer of cryopreserved human embryos with further cleavage after thawing increases delivery and implantation rates 总被引:6,自引:10,他引:6
Van der Elst J; Van den Abbeel E; Vitrier S; Camus M; Devroey P; Van Steirteghem AC 《Human reproduction (Oxford, England)》1997,12(7):1513-1521
We investigated whether further in-vitro culture of human multicellular
embryos that survive cryopreservation can select the viable embryos for
transfer. Embryos for cryopreservation were supernumerary multicellular
embryos obtained after in-vitro fertilization (IVF) and intracytoplasmic
sperm injection (ICSI) treatments, with <20% of their volume filled with
anucleate fragments. These had been cryopreserved using a slow-freezing and
slow-thawing protocol with 1.5 M dimethylsulphoxide as the cryoprotectant.
From the start of our cryopreservation programme until September 12, 1994,
the thawing strategy was to thaw frozen embryos up to the exact number
needed for transfer. Embryos for transfer were selected on the basis of
their morphological appearance and embryo transfer to the patient was done
on the day of thawing. From September 12, 1994 onwards we used a more
selective thawing strategy where a cohort of up to a maximum of 12 frozen
embryos per patient is thawed from which embryos of the best morphological
quality, and which are furthest advanced in terms of cleavage after a 24 h
in-vitro culture period in Menezo B2 medium, are selected. We took delivery
rates, embryo implantation rates and birth rates into account to see if
there is any difference between the following three types of transfers
used: 187 transfers exclusively of embryos having continued to cleave after
thawing, 107 mixed transfers of embryos with and without further cleavage
and 53 transfers exclusively of embryos with no further cleavage. The
overall outcome in terms of delivery rate and embryo implantation and birth
rates were not different between the new and the earlier thawing policies
(6.6, 5.2 and 3.6% versus 6.0, 4.1 and 2.7% respectively). Only when a
distinction was made between transfers on the basis of the presence of
embryos with further cleavage, did the advantage of selection on the basis
of cleavage capacity become evident. Significantly higher delivery and
embryo implantation and birth rates (11.2, 7.7 and 6.5% respectively) were
recorded with transfers exclusively of embryos with further cleavage versus
mixed transfers of embryos with and without further cleavage (1.9, 2.9 and
0.6% respectively). Fifty-three transfers exclusively of embryos with no
further cleavage did not lead to any delivery. Our results demonstrate that
selection of human multicellular embryos which survive cryopreservation and
continue to cleave in vitro can significantly improve the delivery rate per
transfer and the implantation rate per transferred embryo.
相似文献
102.
Viability of partially damaged human embryos after cryopreservation 总被引:10,自引:13,他引:10
Van den Abbeel E; Camus M; Van Waesberghe L; Devroey P; Van Steirteghem AC 《Human reproduction (Oxford, England)》1997,12(9):2006-2010
In our centre, embryos are judged to have survived cryopreservation if at
least half of the initial number of blastomeres remain intact. Therefore
both fully intact and partially damaged embryos are transferred. The aim of
this study was to investigate the viability of partially damaged human
embryos after cryopreservation. We retrospectively analysed the
implantation and in-vivo development of embryos which were either fully
intact or had lost some blastomeres after cryopreservation. Oocytes were
collected following stimulation with the gonadotrophin-releasing hormone
(GnRH)-agonist Buserelin and human menopausal gonadotrophin. Supernumerary
multicellular embryos with not more than 20% of their volume filled with
anucleate fragments were frozen on day 2 or day 3 of the cycle using a slow
cooling procedure with dimethylsulphoxide as the cryoprotectant. Following
slow thawing, 431 fully intact embryos were transferred in 314 embryo
transfer procedures and 488 partially damaged embryos were transferred in
327 such procedures. The percentage of gestational sacs with fetal
heartbeat obtained after transfer of fully intact embryos was almost three
times higher than that after transfer of partially damaged embryos (11.4
versus 3.5%). Forty-five children (birth rate 10% per embryo transfer) were
born after transfer of fully intact embryos and 14 after transfer of
embryos from which some blastomeres had been lost following
cryopreservation. In conclusion, although children have been delivered
after transfer of partially damaged embryos, the aim of a cryopreservation
programme must be to obtain fully intact embryos after thawing.
相似文献
103.
The syndrome of inappropriate secretion of antidiuretic hormone after carotid endarterectomy is very rare; only two cases have been reported in medical literature. We describe the case of an 82-year-old woman presenting with lethargy and drowsiness due to severe hyponatremia with urine hyperosmolarity and plasma hypo-osmolarity after carotid endarterectomy. 相似文献
104.
黄高升 《中国医学科学杂志(英文版)》1994,9(1):16-19
CORRELATIONBETWEENTHENUMBEROFMITOTICFIGURESANDTHEPERCENTAGEOFKi67-POSITIVECELLS INNON-HODGKIN’SLYMPHOMASHuangGaosheng;(黄高升)Fe... 相似文献
105.
Rabbits fed a vitamin E-deficient diet developed severe muscular dystrophy in 3-4 wk, but they did not become anemic. Nevertheless, reticulocyte counts increased in deficient rabbits (3.2%) compared to control rabbits (0.9%), and erythroid hyperplasia was evident in the bone marrow. Comparing deficient rabbits to controls, the plasma iron concentration was lower (134.4 versus 206.6 microgram/dl); the TIBC was higher (335.9 versus 228.3 microgram/dl); the whole blood protoporphyrin concentration was higher (131.6 versus 81.7 microgram/dl); and the total iron content was lower in spleen (71 versus 153 microgram), higher in skeletal muscle (4956 versus 3054 microgram), and unchanged in bone marrow, liver, and heart. Studies of iron absorption and excretion using 59Fe showed no abnormalities in deficient rabbits. There were abnormalities of ferrokinetics, however. The half-time of disappearance of 59Fe was shorter (100.6 versus 169.4 min), the plasma iron turnover was greater (1.25 versus 0.95 mg/dl blood/day), and the reappearance of 59Fe in circulating erythrocytes at day 9 was greater (77.2% versus 57.2%) in deficient rabbits. Anemia induced by phlebotomy accentuated the abnormal iron metabolism of deficient rabbits, and the animals were unable to correct the anemia. These findings show that vitamin E deficiency in rabbits causes abnormal erythropoiesis associated with abnormal iron metabolism and sequestration of iron in skeletal muscle. 相似文献
106.
107.
108.
Effects of cholinergic modulation on responses of neocortical neurons to fluctuating input 总被引:1,自引:0,他引:1
Neocortical neurons in vivo are spontaneously active and intracellular
recordings have revealed strongly fluctuating membrane potentials arising
from the irregular arrival of excitatory and inhibitory synaptic
potentials. In addition to these rapid fluctuations, more slowly varying
influences from diffuse activation of neuromodulatory systems alter the
excitability of cortical neurons by modulating a variety of potassium
conductances. In particular, acetylcholine, which effects learning and
memory, reduces the slow alterhyperpolarization, which contributes to spike
frequency adaptation. We used whole-cell patch-clamp recordings of
pyramidal neurons in neocortical slices and computational simulations to
show, first, that when fluctuating inputs were added to a constant current
pulse, spike frequency adaptation was reduced as the amplitude of the
fluctuations was increased. High- frequency, high-amplitude fluctuating
inputs that resembled in vivo conditions exhibited only weak spike
frequency adaptation. Second, bath application of carbachol, a cholinergic
agonist, significantly increased the firing rate in response to a
fluctuating input but minimally displaced the spike times by < 3 ms,
comparable to the spike jitter observed when a visual stimulus is repeated
under in vivo conditions. These results suggest that cholinergic modulation
may preserve information encoded in precise spike timing, but not in
interspike intervals, and that cholinergic mechanisms other than those
involving adaptation may contribute significantly to cholinergic modulation
of learning and memory.
相似文献
109.
Abstract Protein-chemical and molecular studies were conducted on all osteogenesis imperfecta (OI) type III/IV patients referred to our hospital during the last 15 y. Of a total of 16 OI type III/IV patients studied, 15 patients were heterozygous for a mutation in one of the two genes coding for collagen I, COL1A1 or COL1A2. Cultured fibroblasts from these 15 patients produced both normal and abnormal collagen I molecules, pointing to a dominant-negative effect of the mutation. Nine mutations had not been described previously. Parental mosaicism was demonstrated in three families. In the 16th child the causative mutation was not found. In conclusion, OI type III/IV in most patients of Western European ancestry is caused by dominant mutations in the genes for collagen I, and recurrence of OI is caused in most cases by parental gonadal mosaicism. 相似文献
110.